An explosion in the historic Plaka district of Athens on Saturday night collapsed a three‑storey building that housed a holiday‑rental property, killing two people and leaving a British national among four others missing.

The blast, which occurred two streets from the Acropolis and the Temple of Olympian Zeus, is believed to have been caused by a gas leak. Firefighters, police and rescue teams have combed through piles of rubble, using excavators and thermal imaging cameras to search for survivors.

Reports indicate that an American man and woman were killed, with two additional U.S. tourists unaccounted for. A Greek national and a fellow U.K. citizen who lived in the building are also missing. Their bodies have not yet been recovered.

Authorities confirmed the missing status of the tourists after they failed to appear for their scheduled flight at Athens International Airport, according to Reuters citing local police.

Mayor Haris Doukas described the incident as “an incredible disaster,” while neighbouring buildings suffered damage and debris was scattered across the street.

The British Foreign Office has expressed concern and affirmed that it is in contact with local authorities following the explosion.